The present invention relates to a continuous process for producing hydrogen and sulphur from hydrogen sulfide.
Hydrogen sulfide is one of the commonest by-products of petroleum refining operations and therefore the question of its separation and utilization arises.
As is known, the sulfur contained in crude petroleum tends to accumulate in the heavy fractions obtained from the primary distillation of the petroleum. These heavy fractions are subjected to hydro-desulfuration so as to produce fuel oils which are non-polluting or only slightly polluting.
Other sources of hydrogen sulfide are natural gas and synthetic gases obtained by cracking of certain petroleum cuts or of carbon. The hydrogen sulfide is generally removed from these gases by scrubbing with an alkaline solution.
According to a method widely used in the art, the sulfur is then recovered by partial combustion of the hydrogen sulfide once the latter has been isolated. This results in wastage of the hydrogen which burns to form water.
It is now felt desirable to recover the hydrogen together with the sulfur, especially in view of the fact that the hydro-desulfuration operations require large quantities of hydrogen resulting in high costs of the refined products.
Recovery of the sulfur and hydrogen by simple thermal decomposition of the hydrogen sulfide is not industrially expedient because of the excessively high temperatures needed to shift the equilibrium in favour of the dissociation products.
The object of the present invention is to provide an economically viable method of recovering both hydrogen and sulfur from hydrogen sulfide.